Intense ultra-broadband down-conversion in co-doped oxide glass by multipolar interaction process

Area of Science:

• Materials Science
• Solid-State Physics
• Photovoltaics

Background:

• Europium (Eu2+) and Ytterbium (Yb3+) ions are key elements in luminescent materials.
• Efficient energy transfer is crucial for advanced optical and energy applications.
• Oxide glasses offer a stable and versatile host matrix for rare-earth ions.

Purpose of the Study:

• To investigate Eu(2+) as a sensitizer for Yb(3+) in oxide glass.
• To evaluate the potential of this system as a broadband absorber for blue solar spectra.
• To assess its suitability as a down-conversion layer for solar cells.

Main Methods:

• Synthesis of oxide glass doped with Eu(2+) and Yb(3+).
• Optical characterization including absorption and emission spectroscopy.
• Excitation using a xenon lamp to observe characteristic transitions.

Main Results:

• Observed greenish 4f → 5d transition of Eu(2+) and near-infrared emission of Yb(3+).
• Demonstrated tunable 5d energy levels of Eu(2+) by host modification.
• Achieved high energy transfer efficiency and a quantum efficiency up to 163.8%.

Conclusions:

• Eu(2+) efficiently sensitizes Yb(3+) in oxide glass, acting as a broadband blue light absorber.
• The system exhibits excellent mechanical, thermal, and chemical stability.
• This material is a promising candidate for down-conversion layers in solar cells.